Not everybody wants images to be restored. Many who want to use an image in a paper or blog post will prefer a cleaned-up version. On the other hand, some researchers are primarily interested in exactly what is removed by image restoration: the texture of the paper, the degradation of an old photograph. Wikimedia Commons' solution to this trade-off is to allow access to multiple versions. This is an example of non-paternalism: giving choices to the user rather than making them on their behalf.
There are two senses in which Commons gives access to multiple versions of a file. A slightly changed file can be uploaded as a new version: the software will show the most recent by default but older versions are still available. "Hyder Khan of Ghazni", shared by the British Library, has nicely vivid colours as a result of digital restoration. The older, unrestored versions are still linked under "File history".
More substantial changes can be uploaded as a separate version with a link back to the original. Freedom to do this comes naturally from the free licences. A major change might be a drastic restoration or it might create a derivative work, for example extracting a portrait of Albert Einstein from a group photo.
The Commons page for each file shows where the file is embedded on other Wikimedia sites, including Wikipedia. Daily view statistics for Wikipedia pages are also public. This data is all machine-readable, allowing the creation of software tools that track total views of a batch of images. This is how the British Museum can demonstrate more than 27,000 uses of its images across Wikimedia by the start of 2014 and how the Archivist of the United States was able to announce one billion hits during 2013 on the National Archives’ content shared through Wikimedia.